release/src-rt-6.x.4708/linux/linux-2.6.36/arch/m68knommu/kernel/process.c

   1 /*
   2  *  linux/arch/m68knommu/kernel/process.c
   3  *
   4  *  Copyright (C) 1995  Hamish Macdonald
   5  *
   6  *  68060 fixes by Jesper Skov
   7  *
   8  *  uClinux changes
   9  *  Copyright (C) 2000-2002, David McCullough <davidm@snapgear.com>
  10  */
  11
  12 /*
  13  * This file handles the architecture-dependent parts of process handling..
  14  */
  15
  16 #include <linux/module.h>
  17 #include <linux/errno.h>
  18 #include <linux/sched.h>
  19 #include <linux/kernel.h>
  20 #include <linux/mm.h>
  21 #include <linux/smp.h>
  22 #include <linux/smp_lock.h>
  23 #include <linux/stddef.h>
  24 #include <linux/unistd.h>
  25 #include <linux/ptrace.h>
  26 #include <linux/user.h>
  27 #include <linux/interrupt.h>
  28 #include <linux/reboot.h>
  29 #include <linux/fs.h>
  30 #include <linux/slab.h>
  31
  32 #include <asm/uaccess.h>
  33 #include <asm/system.h>
  34 #include <asm/traps.h>
  35 #include <asm/machdep.h>
  36 #include <asm/setup.h>
  37 #include <asm/pgtable.h>
  38
  39 asmlinkage void ret_from_fork(void);
  40
  41 /*
  42  * The following aren't currently used.
  43  */
  44 void (*pm_idle)(void);
  45 EXPORT_SYMBOL(pm_idle);
  46
  47 void (*pm_power_off)(void);
  48 EXPORT_SYMBOL(pm_power_off);
  49
  50 /*
  51  * The idle loop on an m68knommu..
  52  */
  53 static void default_idle(void)
  54 {
  55         local_irq_disable();
  56         while (!need_resched()) {
  57                 /* This stop will re-enable interrupts */
  58                 __asm__("stop #0x2000" : : : "cc");
  59                 local_irq_disable();
  60         }
  61         local_irq_enable();
  62 }
  63
  64 void (*idle)(void) = default_idle;
  65
  66 /*
  67  * The idle thread. There's no useful work to be
  68  * done, so just try to conserve power and have a
  69  * low exit latency (ie sit in a loop waiting for
  70  * somebody to say that they'd like to reschedule)
  71  */
  72 void cpu_idle(void)
  73 {
  74         /* endless idle loop with no priority at all */
  75         while (1) {
  76                 idle();
  77                 preempt_enable_no_resched();
  78                 schedule();
  79                 preempt_disable();
  80         }
  81 }
  82
  83 void machine_restart(char * __unused)
  84 {
  85         if (mach_reset)
  86                 mach_reset();
  87         for (;;);
  88 }
  89
  90 void machine_halt(void)
  91 {
  92         if (mach_halt)
  93                 mach_halt();
  94         for (;;);
  95 }
  96
  97 void machine_power_off(void)
  98 {
  99         if (mach_power_off)
 100                 mach_power_off();
 101         for (;;);
 102 }
 103
 104 void show_regs(struct pt_regs * regs)
 105 {
 106         printk(KERN_NOTICE "\n");
 107         printk(KERN_NOTICE "Format %02x  Vector: %04x  PC: %08lx  Status: %04x    %s\n",
 108                regs->format, regs->vector, regs->pc, regs->sr, print_tainted());
 109         printk(KERN_NOTICE "ORIG_D0: %08lx  D0: %08lx  A2: %08lx  A1: %08lx\n",
 110                regs->orig_d0, regs->d0, regs->a2, regs->a1);
 111         printk(KERN_NOTICE "A0: %08lx  D5: %08lx  D4: %08lx\n",
 112                regs->a0, regs->d5, regs->d4);
 113         printk(KERN_NOTICE "D3: %08lx  D2: %08lx  D1: %08lx\n",
 114                regs->d3, regs->d2, regs->d1);
 115         if (!(regs->sr & PS_S))
 116                 printk(KERN_NOTICE "USP: %08lx\n", rdusp());
 117 }
 118
 119 /*
 120  * Create a kernel thread
 121  */
 122 int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
 123 {
 124         int retval;
 125         long clone_arg = flags | CLONE_VM;
 126         mm_segment_t fs;
 127
 128         fs = get_fs();
 129         set_fs(KERNEL_DS);
 130
 131         __asm__ __volatile__ (
 132                         "movel  %%sp, %%d2\n\t"
 133                         "movel  %5, %%d1\n\t"
 134                         "movel  %1, %%d0\n\t"
 135                         "trap   #0\n\t"
 136                         "cmpl   %%sp, %%d2\n\t"
 137                         "jeq    1f\n\t"
 138                         "movel  %3, %%sp@-\n\t"
 139                         "jsr    %4@\n\t"
 140                         "movel  %2, %%d0\n\t"
 141                         "trap   #0\n"
 142                         "1:\n\t"
 143                         "movel  %%d0, %0\n"
 144                 : "=d" (retval)
 145                 : "i" (__NR_clone),
 146                   "i" (__NR_exit),
 147                   "a" (arg),
 148                   "a" (fn),
 149                   "a" (clone_arg)
 150                 : "cc", "%d0", "%d1", "%d2");
 151
 152         set_fs(fs);
 153         return retval;
 154 }
 155
 156 void flush_thread(void)
 157 {
 158 #ifdef CONFIG_FPU
 159         unsigned long zero = 0;
 160 #endif
 161         set_fs(USER_DS);
 162         current->thread.fs = __USER_DS;
 163 #ifdef CONFIG_FPU
 164         if (!FPU_IS_EMU)
 165                 asm volatile (".chip 68k/68881\n\t"
 166                               "frestore %0@\n\t"
 167                               ".chip 68k" : : "a" (&zero));
 168 #endif
 169 }
 170
 171 /*
 172  * "m68k_fork()".. By the time we get here, the
 173  * non-volatile registers have also been saved on the
 174  * stack. We do some ugly pointer stuff here.. (see
 175  * also copy_thread)
 176  */
 177
 178 asmlinkage int m68k_fork(struct pt_regs *regs)
 179 {
 180         /* fork almost works, enough to trick you into looking elsewhere :-( */
 181         return(-EINVAL);
 182 }
 183
 184 asmlinkage int m68k_vfork(struct pt_regs *regs)
 185 {
 186         return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, rdusp(), regs, 0, NULL, NULL);
 187 }
 188
 189 asmlinkage int m68k_clone(struct pt_regs *regs)
 190 {
 191         unsigned long clone_flags;
 192         unsigned long newsp;
 193
 194         /* syscall2 puts clone_flags in d1 and usp in d2 */
 195         clone_flags = regs->d1;
 196         newsp = regs->d2;
 197         if (!newsp)
 198                 newsp = rdusp();
 199         return do_fork(clone_flags, newsp, regs, 0, NULL, NULL);
 200 }
 201
 202 int copy_thread(unsigned long clone_flags,
 203                 unsigned long usp, unsigned long topstk,
 204                 struct task_struct * p, struct pt_regs * regs)
 205 {
 206         struct pt_regs * childregs;
 207         struct switch_stack * childstack, *stack;
 208         unsigned long *retp;
 209
 210         childregs = (struct pt_regs *) (task_stack_page(p) + THREAD_SIZE) - 1;
 211
 212         *childregs = *regs;
 213         childregs->d0 = 0;
 214
 215         retp = ((unsigned long *) regs);
 216         stack = ((struct switch_stack *) retp) - 1;
 217
 218         childstack = ((struct switch_stack *) childregs) - 1;
 219         *childstack = *stack;
 220         childstack->retpc = (unsigned long)ret_from_fork;
 221
 222         p->thread.usp = usp;
 223         p->thread.ksp = (unsigned long)childstack;
 224
 225         if (clone_flags & CLONE_SETTLS)
 226                 task_thread_info(p)->tp_value = regs->d5;
 227
 228         /*
 229          * Must save the current SFC/DFC value, NOT the value when
 230          * the parent was last descheduled - RGH  10-08-96
 231          */
 232         p->thread.fs = get_fs().seg;
 233
 234 #ifdef CONFIG_FPU
 235         if (!FPU_IS_EMU) {
 236                 /* Copy the current fpu state */
 237                 asm volatile ("fsave %0" : : "m" (p->thread.fpstate[0]) : "memory");
 238
 239                 if (p->thread.fpstate[0])
 240                   asm volatile ("fmovemx %/fp0-%/fp7,%0\n\t"
 241                                 "fmoveml %/fpiar/%/fpcr/%/fpsr,%1"
 242                                 : : "m" (p->thread.fp[0]), "m" (p->thread.fpcntl[0])
 243                                 : "memory");
 244                 /* Restore the state in case the fpu was busy */
 245                 asm volatile ("frestore %0" : : "m" (p->thread.fpstate[0]));
 246         }
 247 #endif
 248
 249         return 0;
 250 }
 251
 252 /* Fill in the fpu structure for a core dump.  */
 253
 254 int dump_fpu(struct pt_regs *regs, struct user_m68kfp_struct *fpu)
 255 {
 256 #ifdef CONFIG_FPU
 257         char fpustate[216];
 258
 259         if (FPU_IS_EMU) {
 260                 int i;
 261
 262                 memcpy(fpu->fpcntl, current->thread.fpcntl, 12);
 263                 memcpy(fpu->fpregs, current->thread.fp, 96);
 264                 /* Convert internal fpu reg representation
 265                  * into long double format
 266                  */
 267                 for (i = 0; i < 24; i += 3)
 268                         fpu->fpregs[i] = ((fpu->fpregs[i] & 0xffff0000) << 15) |
 269                                          ((fpu->fpregs[i] & 0x0000ffff) << 16);
 270                 return 1;
 271         }
 272
 273         /* First dump the fpu context to avoid protocol violation.  */
 274         asm volatile ("fsave %0" :: "m" (fpustate[0]) : "memory");
 275         if (!fpustate[0])
 276                 return 0;
 277
 278         asm volatile ("fmovem %/fpiar/%/fpcr/%/fpsr,%0"
 279                 :: "m" (fpu->fpcntl[0])
 280                 : "memory");
 281         asm volatile ("fmovemx %/fp0-%/fp7,%0"
 282                 :: "m" (fpu->fpregs[0])
 283                 : "memory");
 284 #endif
 285         return 1;
 286 }
 287
 288 /*
 289  *      Generic dumping code. Used for panic and debug.
 290  */
 291 void dump(struct pt_regs *fp)
 292 {
 293         unsigned long   *sp;
 294         unsigned char   *tp;
 295         int             i;
 296
 297         printk(KERN_EMERG "\nCURRENT PROCESS:\n\n");
 298         printk(KERN_EMERG "COMM=%s PID=%d\n", current->comm, current->pid);
 299
 300         if (current->mm) {
 301                 printk(KERN_EMERG "TEXT=%08x-%08x DATA=%08x-%08x BSS=%08x-%08x\n",
 302                         (int) current->mm->start_code,
 303                         (int) current->mm->end_code,
 304                         (int) current->mm->start_data,
 305                         (int) current->mm->end_data,
 306                         (int) current->mm->end_data,
 307                         (int) current->mm->brk);
 308                 printk(KERN_EMERG "USER-STACK=%08x KERNEL-STACK=%08x\n\n",
 309                         (int) current->mm->start_stack,
 310                         (int)(((unsigned long) current) + THREAD_SIZE));
 311         }
 312
 313         printk(KERN_EMERG "PC: %08lx\n", fp->pc);
 314         printk(KERN_EMERG "SR: %08lx    SP: %08lx\n", (long) fp->sr, (long) fp);
 315         printk(KERN_EMERG "d0: %08lx    d1: %08lx    d2: %08lx    d3: %08lx\n",
 316                 fp->d0, fp->d1, fp->d2, fp->d3);
 317         printk(KERN_EMERG "d4: %08lx    d5: %08lx    a0: %08lx    a1: %08lx\n",
 318                 fp->d4, fp->d5, fp->a0, fp->a1);
 319         printk(KERN_EMERG "\nUSP: %08x   TRAPFRAME: %p\n",
 320                 (unsigned int) rdusp(), fp);
 321
 322         printk(KERN_EMERG "\nCODE:");
 323         tp = ((unsigned char *) fp->pc) - 0x20;
 324         for (sp = (unsigned long *) tp, i = 0; (i < 0x40);  i += 4) {
 325                 if ((i % 0x10) == 0)
 326                         printk(KERN_EMERG "%p: ", tp + i);
 327                 printk("%08x ", (int) *sp++);
 328         }
 329         printk(KERN_EMERG "\n");
 330
 331         printk(KERN_EMERG "KERNEL STACK:");
 332         tp = ((unsigned char *) fp) - 0x40;
 333         for (sp = (unsigned long *) tp, i = 0; (i < 0xc0); i += 4) {
 334                 if ((i % 0x10) == 0)
 335                         printk(KERN_EMERG "%p: ", tp + i);
 336                 printk("%08x ", (int) *sp++);
 337         }
 338         printk(KERN_EMERG "\n");
 339
 340         printk(KERN_EMERG "USER STACK:");
 341         tp = (unsigned char *) (rdusp() - 0x10);
 342         for (sp = (unsigned long *) tp, i = 0; (i < 0x80); i += 4) {
 343                 if ((i % 0x10) == 0)
 344                         printk(KERN_EMERG "%p: ", tp + i);
 345                 printk("%08x ", (int) *sp++);
 346         }
 347         printk(KERN_EMERG "\n");
 348 }
 349
 350 /*
 351  * sys_execve() executes a new program.
 352  */
 353 asmlinkage int sys_execve(const char *name,
 354                           const char *const *argv,
 355                           const char *const *envp)
 356 {
 357         int error;
 358         char * filename;
 359         struct pt_regs *regs = (struct pt_regs *) &name;
 360
 361         filename = getname(name);
 362         error = PTR_ERR(filename);
 363         if (IS_ERR(filename))
 364                 return error;
 365         error = do_execve(filename, argv, envp, regs);
 366         putname(filename);
 367         return error;
 368 }
 369
 370 unsigned long get_wchan(struct task_struct *p)
 371 {
 372         unsigned long fp, pc;
 373         unsigned long stack_page;
 374         int count = 0;
 375         if (!p || p == current || p->state == TASK_RUNNING)
 376                 return 0;
 377
 378         stack_page = (unsigned long)p;
 379         fp = ((struct switch_stack *)p->thread.ksp)->a6;
 380         do {
 381                 if (fp < stack_page+sizeof(struct thread_info) ||
 382                     fp >= THREAD_SIZE-8+stack_page)
 383                         return 0;
 384                 pc = ((unsigned long *)fp)[1];
 385                 if (!in_sched_functions(pc))
 386                         return pc;
 387                 fp = *(unsigned long *) fp;
 388         } while (count++ < 16);
 389         return 0;
 390 }
 391
 392 /*
 393  * Return saved PC of a blocked thread.
 394  */
 395 unsigned long thread_saved_pc(struct task_struct *tsk)
 396 {
 397         struct switch_stack *sw = (struct switch_stack *)tsk->thread.ksp;
 398
 399         /* Check whether the thread is blocked in resume() */
 400         if (in_sched_functions(sw->retpc))
 401                 return ((unsigned long *)sw->a6)[1];
 402         else
 403                 return sw->retpc;
 404 }